fixed roles for mysql

Former-commit-id: a517fb14

roles/mysql/tasks/main.yml

 ---
 - include_vars: "{{ ansible_distribution }}_{{ ansible_distribution_major_version }}.yml"
 - include: "{{ ansible_distribution }}_{{ ansible_distribution_major_version }}_{{ mysql_type }}.yml"
+- include: mysql_client.yml
\ No newline at end of file

roles/mysql/vars/Ubuntu_18.yml

@@ -6,6 +6,7 @@ server_packages:
  - libapache2-mod-wsgi
  - python-mysql.connector
  - mariadb-server
+ - python-mysqldb
 
 client_packages:
  - python